Finding Earth's Mass Using Gauss Law

Click For Summary
SUMMARY

The mass of the Earth can be calculated using Gauss's Law for gravitation, which states that the gravitational flux through a closed surface is proportional to the total mass within that volume. Given the Earth's volume mass density function ρ = A - Br/R, where A = 1.42 x 104 kg/m3, B = 1.16 x 104 kg/m3, and Earth's radius R = 6.370 x 106 m, one can derive the mass M by integrating the density over the volume of the Earth. The gravitational constant G is approximately 6.673 x 10-11 N m2/kg2, which is essential for calculations involving gravitational forces.

PREREQUISITES
  • Understanding of Gauss's Law for gravitation
  • Familiarity with spherical coordinates and volume integration
  • Knowledge of gravitational constant G
  • Basic concepts of mass density and its mathematical representation
NEXT STEPS
  • Calculate the mass of the Earth using the provided density function and integration techniques
  • Explore the implications of Gauss's Law in gravitational fields
  • Study the derivation of gravitational flux and its applications in astrophysics
  • Learn about the significance of the gravitational constant G in various physical equations
USEFUL FOR

Students and professionals in physics, astrophysics, and engineering who are interested in gravitational calculations and the physical properties of celestial bodies.

bananasplit
Messages
7
Reaction score
0
Is it possible to find the mass of the Earth based on the Earth's volume mass density, roe = A-Br=R, where A = 1.42 x 104 kg/m3, B = 1.16 x 104 kg/m3, and Earth’s radius
R = 6.370 x 106 m

I know that based on Gauss Law that (closed integral) g x da = -4Gmin, where g is the total electric field due to the inside and outside of the closed surface. I don't see how this is possible.
 
Last edited:
Physics news on Phys.org
Your equation and the units don't make sense.
 
This was the entire question
Consider a closed surface S in a region of gravitational field g. Gauss’s law for gravitation tells us that the gravitational flux through surface S is linearly proportional to the total mass min occupying the volume contained by S. More specifically, Gauss’s law states that
(closed integral)g x da = -4Gmin :
Note that g here is the total electric field, due to mass sources both inside and outside S. The value of G, the gravitational constant, is about 6.673 x10-11 N m2/kg2.
(a) Earth’s volume mass density, at any distance r from its center, is given approximately by the function p = A-Br/R, where A = 1.42 x 104 kg/m3, B = 1.16 x 104 kg/m3, and Earth’s radius R = 6.370 x 106 m. Calculate the numerical value of Earth’s mass M. Hint: The volume of a
spherical shell, lying between radii r and r + dr, is dv = 4(pie)r2dr.
 
Last edited:

Similar threads

Replies
6
Views
2K
  • · Replies 26 ·
Replies
26
Views
3K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
Replies
21
Views
4K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 7 ·
Replies
7
Views
2K